On the relationship between period and cohort mortality

In this paper I explore the formal relationship between period and cohort mortality, focusing on a comparison of measures of mean lifespan. I consider not only the usual measures (life expectancy at birth for time periods and birth cohorts) but also some alternative measures that have been proposed recently. I examine (and reject) the claim made by Bongaarts and Feeney that the level of period is distorted, or biased, due to changes in the timing of mortality. I show that their proposed alternative measure, called “tempo-adjusted†life expectancy, is exactly equivalent in its generalized form to a measure proposed by both Brouard and Guillot, the cross-sectional average length of life (or CAL), which substitutes cohort survival probabilities for their period counterparts in the calculation of mean lifespan. I conclude that this measure does not in any sense correct for a distortion in period life expectancy at birth, but rather offers an alternative measure of mean lifespan that is approximately equal to two analytically interesting quantities: 1) the mean age at death in a given year for a hypothetical population subject to observed historical mortality conditions but with a constant annual number of births; and 2) the mean age at death, , for a cohort born years ago. However, I also observe that the trend in period does indeed offer a biased depiction of the pace of change in mean lifespan from cohort to cohort. Holding other factors constant, an historical increase in life expectancy at birth is somewhat faster when viewed from the perspective of cohorts (i.e., year of birth) than from the perspective of periods (i.e., year of death).life expectancy, life span, mortality, tempo-adjusted life expectancy

The Cancer Transition in Japan since 1951

The overall trend of cancer mortality in Japan has been decreasing since the 1960s (age-standardized death rates for ages 30-69), though trends differ enormously among various forms of the disease. Cancer mortality was heavily influenced by Japanese postwar economic recovery, which led to improved living conditions and better control of infectious agents known to cause some common forms of cancer (stomach, cervical). However, Japanese wealth and development have also been associated with risky personal behaviors (smoking, drinking) and other conditions, leading to increases in cancers with no known or else very weak links to infection. This shift away from infectious and toward non-infectious causes of prevalent forms of cancers is called the "cancer transition," by analogy to Omran's "epidemiologic transition." We suggest that the cancer transition described here in the case of Japan must be a part of efforts to revise and update the epidemiologic transition, which should incorporate new knowledge about the role of infection in chronic disease morbidity and mortality.cancer, cancer transition, epidemiologic transition, health, health and development, infectious diseases, Japan, mortality, non-infectious disease

Introduction to the Special Collection “Human Mortality over Age, Time, Sex, and Place: The 1st HMD Symposiumâ€

This introduction to the special collection “Human Mortality over Age, Time, Sex, and Place: The 1st HMD Symposium†describes the Human Mortality Database project and briefly summarizes the Special Collection articles.

The Role of Inflammatory Mediators in the Pathogenesis of Otitis Media and Sequelae

This review deals with the characteristics of various inflammatory mediators identified in the middle ear during otitis media and in cholesteatoma. The role of each inflammatory mediator in the pathogenesis of otitis media and cholesteatoma has been discussed. Further, the relation of each inflammatory mediator to the pathophysiology of the middle and inner ear along with its mechanisms of pathological change has been described. The mechanisms of hearing loss including sensorineural hearing loss (SNHL) as a sequela of otitis media are also discussed. The passage of inflammatory mediators through the round window membrane into the scala tympani is indicated. In an experimental animal model, an application of cytokines and lipopolysaccharide (LPS), a bacterial toxin, on the round window membrane induced sensorineural hearing loss as identified through auditory brainstem response threshold shifts. An increase in permeability of the blood-labyrinth barrier (BLB) was observed following application of these inflammatory mediators and LPS. The leakage of the blood components into the lateral wall of the cochlea through an increase in BLB permeability appears to be related to the sensorineural hearing loss by hindering K+ recycling through the lateral wall disrupting the ion homeostasis of the endolymph. Further studies on the roles of various inflammatory mediators and bacterial toxins in inducing the sensorineumral hearing loss in otitis media should be pursued

The Reproductive Revolution

Este texto fue publicado en 2009 por The Sociological Review. Rogamos que, a efectos de divulgación, docencia y cita bibliográfica se acuda a la publicación impresa (u online de la propia revista) y la cita sea esta: MacInnes, J., Pérez Díaz, J. (2009), "The reproductive revolution" The Sociological Review 57 (2): 262-284. Su versión html puede encontrarse en esta dirección:http://www3.interscience.wiley.com/cgi-bin/fulltext/122368561/HTMLSTART Quienes estén interesados en ampliar la información sobre nuestra Teoría de la Revolución Reproductiva pueden visitar la página web siguiente: http://www.ieg.csic.es/jperez/pags/RRweb/RRweb.htm También encontrarán en este mismo repositorio otra publicación con unaexposición en castellano de las mismas ideas y publicada en la REIS bajo el título “La tercera revolución de la modernidad: la reproductiva”.We suggest that a third revolution alongside the better known economic and political ones has been vital to the rise of modernity: the reproductive revolution, comprising a historically unrepeatable shift in the efficiency of human reproduction which for the first time brought demographic security.As well as highlighting the contribution of demographic change to the rise of modernity and addressing the limitations of orthodox theories of the demographic transition, the concept of the reproductive revolution offers a better way to integrate sociology and demography. The former has tended to pay insufficient heed to sexual reproduction, individual mortality and the generational replacement of population, while the latter has undervalued its own distinctive theoretical contribution, portraying demographic change as the effect of causes lying elsewhere. We outline a theory of the reproductive revolution, review some relevant supporting empirical evidence and briefly discuss its implications both for demographic transition theory itself, and for a range of key social changes that we suggest it made possible: the decline of patriarchy and feminisation of the public sphere, the deregulation and privatisation of sexuality, family change, the rise of identity, ‘low’ fertility and ‘population ageing’.Peer reviewe

On the relationship between period and cohort mortality

In this paper I explore the formal relationship between period and cohort mortality, focusing on a comparison of measures of mean lifespan. I consider not only the usual measures (life expectancy at birth for time periods and birth cohorts) but also some alternative measures that have been proposed recently. I examine (and reject) the claim made by Bongaarts and Feeney that the level of period is distorted, or biased, due to changes in the timing of mortality. I show that their proposed alternative measure, called "tempo-adjusted" life expectancy, is exactly equivalent in its generalized form to a measure proposed by both Brouard and Guillot, the cross-sectional average length of life (or CAL), which substitutes cohort survival probabilities for their period counterparts in the calculation of mean lifespan. I conclude that this measure does not in any sense correct for a distortion in period life expectancy at birth, but rather offers an alternative measure of mean lifespan that is approximately equal to two analytically interesting quantities: 1) the mean age at death in a given year for a hypothetical population subject to observed historical mortality conditions but with a constant annual number of births; and 2) the mean age at death, , for a cohort born years ago. However, I also observe that the trend in period does indeed offer a biased depiction of the pace of change in mean lifespan from cohort to cohort. Holding other factors constant, an historical increase in life expectancy at birth is somewhat faster when viewed from the perspective of cohorts (i.e., year of birth) than from the perspective of periods (i.e., year of death)